The overall objective of the research is to characterize the allogeneic cytotoxic T cell receptor. The signal transmission from the receptor to the cytoplasm of the cell is being analyzed. The hypothesis is that a spectrin-like molecule, fodrin, found in the cytosol cytoskeleton of lymphocytes is involved in this process. In the past year a crossreactive anti-erythrocyte spectrin antibody has been used to characterize this antigen in lymphocytes. Based on these results antibodies specific for lymphocyte fodrin have been prepared and used to compare the expression of fodrin in B and T lymphocytes. The antibodies are currently being used to analyze cytotoxic T cell lines obtained from Dr. V. Englhard. These cell lines have been selected as mutants which show defects in cytotoxic function which may be related to receptor signalling. The expresson of the alpha and beta chains of the antigen and their ability to co-cap with the receptor is being analyzed. (CS)